What Is Architecture?

A building is the largest thing most people ever make, and the most permanent. It has to stand up against gravity, wind and earthquake for generations; it has to keep out the rain and let in the light; it has to hold the life of a household, a court, a congregation or a city; and, because people have always cared about it, it has to look right. Architecture is the art of meeting all of these demands at once. This book is about the rules that builders, in every age and every part of the world, have worked out for doing so.

The oldest surviving book on the subject puts it in three words. Writing for the emperor Augustus in the last decades before Christ, the Roman engineer Vitruvius said that everything must be built with regard to firmitas, utilitas and venustas (durability, convenience and beauty). In the seventeenth century the English diplomat Sir Henry Wotton turned the phrase into “firmness, commodity and delight”, and it has been the most famous definition of architecture ever since.

℟Firmness, commodity and delight

Every building must satisfy three demands at once: it must stand up (firmitas), serve its purpose (utilitas), and give pleasure to the eye (venustas).

architecture = firmitas + utilitas + venustas

Why architecture has rules

Every craft has rules, but architecture has more than most, and they come from more directions at once. Some are laws of nature. A stone beam can only span so far before it cracks under its own weight; an arch pushes outward at its feet and must be held there; a roof must be steep enough to shed the rain of its climate. These rules were learned by trial and catastrophe long before anyone could calculate them, and they are the same in Egypt and in China.

Some rules come from the human body. Doors are as tall as a person, steps as high as a stride can comfortably climb, windowsills as high as a seated elbow. Vitruvius went further: he argued that the proportions of a temple should imitate the proportions of a well-made human body, in which the foot is a sixth of the height and the face a tenth. The idea that a building is a kind of body (with a base, a middle and a head, with symmetry about a central axis) runs through the whole of Western architecture.

Some rules come from meaning. A temple faced the rising sun, a mosque faces Mecca, a Chinese palace faces south; the most important room is placed on the central axis, the gods live higher than mortals, the ruler’s hall has the steepest roof and the most elaborate brackets. Such rules tell the visitor where to go and what matters.

And some rules are conventions: agreements that could have been otherwise but, once made, give a whole culture a shared language. The five classical orders, the Chinese system of bracket modules, the Gothic mason’s way of deriving a whole cathedral from a square: none of these is required by gravity or by the body, but each makes it possible for thousands of builders to work in harmony, and for anyone who knows the language to read a building at a glance. A style, in this book, is simply such a shared set of rules.

The distinction between natural and conventional rules was first drawn sharply by a French physician, Claude Perrault, in 1683. He noticed that the ancient buildings everyone admired all used different proportions for the same order, and concluded that the proportions were not laws of nature but habits of taste. His argument split the architects of his age, and it suggests a question still worth asking of any rule in this book: is this true everywhere, or only here?

℟Positive and arbitrary beauty

Distinguish positive beauty, which pleases everyone for evident reasons (fine materials, size, precise workmanship, symmetry), from arbitrary beauty, which pleases through custom, including the exact proportions of the orders.

Rules that build

The treatises of the past were written for builders. A rule such as “make the entablature a quarter of the column” is not a description but an instruction: follow it and you will obtain a building of a certain kind. That is what makes architectural rules unusually well suited to a computer. Each figure in this book is produced by a small program, a generator, that reads the rules and builds the geometry from them. The temple at the head of this chapter is what you get when you apply Vitruvius’s rules for an Ionic hexastyle temple with eustyle spacing.

You can therefore do with these figures what you cannot do with a printed plate: turn them round, look underneath, switch from ink to stone to blueprint, and above all change the rule and watch the consequences. Choose a wider intercolumniation and the columns grow thicker; choose Palladio instead of Vignola and every moulding moves. The point is not to produce accurate replicas of famous buildings, though many models are close, but to make the logic of each tradition visible.

Rules across the world

Western architecture has a written tradition that begins with Vitruvius and runs through the Renaissance treatises of Alberti, Serlio, Vignola and Palladio. But it is far from the only one. Chinese builders under the Song dynasty codified their craft in the Yingzao fashi of 1103, with a modular system as rigorous as any Italian’s; Indian temple builders followed the vastu and shilpa texts; Japanese carpenters handed down proportional systems in family manuals; Islamic craftsmen developed geometric methods of astonishing sophistication that they recorded in pattern scrolls rather than books. Other traditions (the Maya, the Inca, the builders of Stonehenge) left no texts, and their rules have to be recovered from the buildings themselves.

This book tries to treat all of them with the same seriousness. Part I sets out the grammar of building that every tradition shares: post and lintel, wall and opening, arch, vault, dome and roof, proportion and number. Part II studies the classical orders in detail, because no other set of rules has been written about so exhaustively. Part III walks through the styles of the world in time, from the megaliths to the parametric present. Part IV opens the library of treatises in which the rules were written down.

What rules cannot do

A word of caution belongs at the start. No building was ever made great by rules alone. The Parthenon obeys the rules of the Doric order, but so do a thousand dull temples; what distinguishes it is a hundred small decisions that no rule prescribes: the curvature of its floor, the lean of its columns, the precise swell of its echinus. The greatest architects knew the rules well enough to know when to bend them: Michelangelo broke the orders deliberately, Borromini bent walls that everyone else kept straight, and the modernists threw out a whole rulebook in order to write a new one.

Rules are the grammar, not the poetry. But no one ever wrote poetry without first learning a language, and the aim of this book is to teach enough of the languages of architecture to read any building you meet, and perhaps to start writing your own.

Beauty, when the appearance of the work is pleasing and in good taste, and when its members are in due proportion according to correct principles of symmetry.